It is reported that Apple is planning to release a somewhat redesigned iPhone in the Fall 2012, and there are also rumors that Apple has plan to use rubber or plastic material similar to that of bumper accessories which are use in new devices, as per BGR.
In all likelihood, this material will be used as a bezel surrounding the front edge of the phone (like the iPhone 3GS bezel) and it will serve two purposes. First, it will join the glass iPhone face with a new aluminum back plate. It will also cover a redesigned antenna system that surrounds the device, allowing Apple to build the rear case out of aluminum without having to use a large plastic insert above the antennas as the company does on its iPad 2 Wi-Fi + 3G. Earlier reports suggested that Apple’s next-generation iPhone will feature an aluminum case similar to the one found on the iPad 2, as well as a larger display around 4 inches.
Well Apple is more likely to release a redesigned iPhone coming year, never the less there is plenty of time for Apple to modify its design plans for the next device.